Homebuying Mistakes: Water Runs Downhill

Lawrence Kostaneski

During my 10 years as a City Engineer, the most frequent complaint heard from home buyers concerned drainage or flooding. While everyone knew that water ran downhill, many ignored this simple concept when they bought their home.

Rainfall can be fickle, and doesn't always reveal its tendencies to someone who has fallen in love with a house: until the basement fills with mud & water, that is. The problem is that the relationship between rainfall and where it will go (runoff) is complex.

Rain falls in unpredictable patterns. A mild shower lasting several hours does not have the same impact as a thunderstorm that dumps several inches of water in a short time. If your house is near an area designed to carry runoff away from the development, it is possible that your house will get wet. Here are a few reasons why.

Rainwater normally flows in streets, or in channels designed for that purpose. These channels can vary in size from a foot deep and 4 feet wide to 10 feet deep and 30 feet wide. If you look carefully around the house, you may notice a small depression that is designed to carry the rain to a nearby street or larger drainage channel.

The problem is that you have no way of knowing if these depressions and channels are large enough to carry the amount of rain that typically falls in your area.

You also may not know if the rain that falls around houses upstream from you is directed such that it will not flow toward your house. While it may be obvious that these houses are "uphill", you can't always determine how the rainfall is directed.

An easy way to find out is to contact the government agency in your area that is responsible for residential development.

The questions to ask are:

is there a history of house or street flooding in the subdivision;

are the channels adequate for the rainfall amounts in the area;

are there any special restrictions or emergency procedures in force.

A 30 minute call could save you a lot. If you can't get a clear and accurate answer to these questions, you may be at some risk of costly property damage. The personal safety of you and your family is also an issue. A 30 minute call or visit could save you a great deal of trouble and expense. Contact your insurance agent, too.

You should compare the information from the government agency with your observation of the house.

Here are some questions you should ask yourself:

Are any door or window openings below the street or channel elevation ?

Is there a sump pump or other device in the house that is obviously used for pumping water ?

Is there any musty smell or water marks that indicate water reaches the house ?

Is the grass matted or is there evidence that mud and silt have washed into the grass ?

Protect your huge investment by asking lots of questions.

Remember that the seller is not always the best source of information!